While Box Supports Multiple IDP connections to a single tenant, it is not possible without the tenant to provide a landing page for login. This is something that multiple other providers already support, and asking the customer to supply their own login page to access Box from multiple IDPs hurts both Box and the customer.

This hurts Box because instead of creating managed and secure users, I now need to juggle 3rd party users and treat them as guests rather than full users. ($)

This hurts customers by not allowing us to administer policies easily for end users as a whole. Larger conglomerate companies do not necessarily always function in the same silo's and if often takes years for them to merge structure if they even merge at all.